7 - Astrophotography

Summary

Overview

Photography gives you a way to record what you see through the telescope. Surprisingly, though, astrophotography does not reproduce what you see visually. In lunar and planetary work, it is very hard to get pictures as sharp as what the eye can see, because the eye can seize moments of atmospheric steadiness in a way that the camera cannot. In deep-sky work, on the other hand, the camera often records far more than the eye could see with the same instrument because film can accumulate light in a long exposure.

This chapter will tell you enough about astrophotography to get you started. It is not a complete guide; for that, see my other book, Astrophotography for the Amateur (Cambridge University Press, 1999).

One word of advice: astrophotography is a matter of skill, not just equipment. It is definitely not a matter of “You press the button, we do the rest” – it is a stiff test of how well you understand your equipment and the principles on which it operates. Never buy a piece of equipment until you know exactly what you'll use it for.

There is also an element of luck. The pictures that you see published in magazines are the work of experienced astrophotographers and are generally the best of many, many tries. Do not expect to equal them immediately.

But some techniques do yield very good pictures even in the hands of a beginner.